cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-4 of 4 results.

A292408 Number of 3-regular maps with 2n vertices on the torus, up to orientation-preserving isomorphisms.

Original entry on oeis.org

1, 5, 46, 669, 11096, 196888, 3596104, 66867564, 1258801076, 23925376862, 458284630844, 8835496339452, 171286387714900, 3336406717216564, 65257828878990784, 1281049596756607960, 25228921286295314736, 498287389997552607290, 9866927329534881618772, 195837489338961245840240
Offset: 1

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Author

Evgeniy Krasko, Sep 15 2017

Keywords

Crossrefs

3-regular maps on the sphere: A112948.
Cf. A292971 (4-regular), A292972 (5-regular), A292974 (6-regular).

A292971 Number of 4-regular maps with n vertices on the torus, up to orientation-preserving isomorphisms.

Original entry on oeis.org

1, 4, 23, 185, 1647, 16455, 169734, 1805028, 19472757, 212603589, 2341275180, 25969695728, 289782412836, 3250137255678
Offset: 1

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Author

Evgeniy Krasko, Sep 27 2017

Keywords

Crossrefs

Cf. A292408 (3-regular), A292972 (5-regular), A292974 (6-regular).

A292974 Number of 6-regular maps with n vertices on the torus, up to orientation-preserving isomorphisms.

Original entry on oeis.org

3, 81, 3313, 171282, 9444158, 541659909, 31819176850, 1902508129720, 115307287484560, 7064528615347192, 436658221692698200, 27188662712300575980, 1703444238720524912060
Offset: 1

Views

Author

Evgeniy Krasko, Sep 27 2017

Keywords

Crossrefs

Cf. A292408 (3-regular), A292971 (4-regular), A292972 (5-regular).

A301425 Number of plane 5-regular simple connected graphs with 2n vertices.

Original entry on oeis.org

1, 0, 1, 1, 6, 14, 98, 529, 4035, 31009, 252386, 2073769, 17277113
Offset: 6

Views

Author

M. F. Hasler, Mar 20 2018

Keywords

Comments

We count here plane graphs, i.e., graphs embedded in the plane, up to embedding-preserving isomorphism, while such sequences as A003094 count planar graphs (counted up to abstract isomorphism). In this we follow the nomenclature of Brendan McKay, cf. link.

Examples

			There is only a(6) = 1 planar 5-regular simple connected graph with 2n = 12 vertices, which is the icosahedral graph, cf. MathWorld link. If we label the vertices 1, ..., 9, A, B, C, they are connected as follows: 1 -> {2 3 4 5 6}, 2 -> {1 6 7 8 3}, 3 -> {1 2 8 9 4}, 4 -> {1 3 9 A 5}, 5 -> {1 4 A B 6}, 6 -> {1 5 B 7 2 }, 7 -> {2 6 B C 8}, 8 -> {2 7 C 9 3}, 9 -> {3 8 C A 4}, A -> {4 9 C B 5}, B -> {5 A C 7 6}, C -> {7 B A 9 8}.
For other numbers of vertices, the number of plane 5-regular simple connected graphs is as follows:
14 vertices: 0  graphs,
16 vertices: 1  graph,
18 vertices: 1  graph,
20 vertices: 6  graphs,
22 vertices: 14  graphs,
24 vertices: 98  graphs,
26 vertices: 529  graphs,
28 vertices: 4035  graphs,
30 vertices: 31009  graphs,
32 vertices: 252386  graphs,
34 vertices: 2073769 graphs,
36 vertices: 17277113 graphs. (From the McKay web page.)
		

Crossrefs

Showing 1-4 of 4 results.